


Superior Genes

by HeroFizzer



Category: Kill la Kill (Anime & Manga)
Genre: Cock Worship, Cuckolding, F/F, Futanari, Lesbian, Multi, Other, Penis Size, Sibling Incest, Small Penis, Uncircumcised Penis, Yuri, ntr, size comparison, small penis humiliation, sph
Language: English
Status: Completed
Published: 2020-12-05
Updated: 2020-12-05
Packaged: 2021-03-09 17:39:48
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,133
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27890131
Author URL: https://archiveofourown.org/users/HeroFizzer/pseuds/HeroFizzer
Summary: Ryuko is off to save Mako from Satsuki again...or so she thinks. The truth is that her friend is really just enjoying the president's cock, namely because there's nothing from Ryuuko for her to worship. It only makes sense, given how well endowed Satsuki gets. (Commissioned)
Relationships: Kiryuuin Satsuki/Mankanshoku Mako, Kiryuuin Satsuki/Matoi Ryuuko, Mankanshoku Mako/Matoi Ryuuko
Kudos: 19





	Superior Genes

“How the hell am I home before Mako? It's HER house...”

Ryuko grumbled to herself, sitting in her regular clothes as she made an attempt to start on her homework. The table inside her only real friend's house was lonesome, especially without the Mankanshoku girl's motor mouth going a million miles a minute. It was the perfect background noise for her, giving her something to ignore and tune out while she managed to do most of the work that would help her and her host's family move out of the poverty line.

The thing was, now she couldn't focus. It was too quiet, peaceful even. The other members of Mako's energetic family were off doing their own thing, so she couldn't even use them as the distraction her ears needed. “I've gotten way too used to her mouth...”

“I bet you have,” scoffed Senketsu, the living sailor uniform that acted as her battle attire, “although I imagine you prefer it being used in other ways.”

“Quiet, you!” Ryuko growled, punching her uniform even if it meant hurting herself. “I know I might not show it but I'm worried sick, especially with Satsuki and her presidents gunning for my head.”

“Considering she had already been used as bait from the tennis club, that's reason enough to be concerned. So why aren't you trying to find her?”

“Because that's exactly what I'm worried about,” Ryuko explained, “and I don't want to jump to any conclusions, either. Let them come to me before I go to them.”

Just as she said that, Ryuko heard a notification go off on her phone. Curious, she gave it a look, seeing a number she had no recollection of before. There was a paper clip symbol next to it, showing that there was something attached to it. “Wonder what this could be?”

“Are you positive you want to open that?” asked Senketsu. “There's something fishy about opening a text from a number you don't recognize.”

“Probably someone who kidnapped Mako and looked through her contacts to let me know where they have her.” Ryuko proceeded to tap on her screen, opening the attachment to see the just what it was. Her eyes went wide at the sight of the first frame as it loaded, revealing Mako with a rope tied around her body, her hands behind her back and attached to the wrappings at her knees. In her mouth was a huge, girthy ten inch rod, one that slammed hard into her face. The brunette winced as it slammed against her, with her throat bulging out with unusual ease. Her mouth was drooling, a mixture of saliva and cum going down her chin, hanging off so far down that it was level with her chest. The balls of the stranger were swinging hard against Mako's face, with strands of the fluids stuck between them when they pulled back.

“Go on,” said the voice, which Ryuko couldn't recognize thanks to the background noise making it barely coherent, “say it. Tell her what I told me.”

Mako pulled back on the rod, taking a long gasp for air before speaking. “I love your cock...” Mako said in an exhausted tone. “I love your big fat cock. I want more of it! More of that huge dick!”

As she kept her mouth open wide, the rod was injected back inside once more, pumping away hard and fast, with more cum and drool coming out of her mouth as a result.

Ryuko shivered, gripping her phone tightly out of anger. Senketsu could sense that she was eager to crush the device, growing furious as her friend continued to willfully suck on such a huge dong. “What the fuck is she doing?!” Ryuko shouted.

“I hope you're seeing this, Ryuko Matoi,” moaned the stranger's voice as Mako continued to bob her head along the huge shaft, “because if you want to see your friend again you're going to have to drag her away from my huge dong.”

“It looks like she's sucking a dick.” said Senketsu. “Finally, something that can actually shut that girl up.”

“That's...that's nothing.” growled Ryuko, trying to hold back her jealousy. And yet, as she watched the video play on repeat following the stranger's threat. The visual of Mako sucking a dick, unable to identify who it belonged to, stirred something inside of the Matoi girl that she couldn't quite explain. All she knew was that it felt very good, although not as satisfying as she could wish for. “I'll show HER a cock to be satisfied with!”

Ryuko flipped up the skirt of Senketsu, sitting back from the table to get a good shot. She pulled her panties to the side, showing off the four inch uncut member that she had grown while viewing Mako sucking on the stranger's staff. The uniform itself caught a glimpse of her genitals, cackling to himself. “Oh yes, having something as thin as a pencil is going to show the owner of a huge dick who the boss is between you!”

“Shut it!” Ryuko said, watching as her member rose up to the occasion. “It's totally gonna outshine that penis! It's not about the size, it's how you use it, you know!”

Senketsu rolled his eye as he sighed. “Yes, you keep telling yourself that while I laugh quietly about your dick size.” Ryuko grumbled as she tried to position her phone's camera for the right angle, but her living suit had a point; no matter what she did, she wasn't going to impress anyone. But she could at least try and hope that it would lead to something better like how her half of the scissor sword she had been carrying around with her. She made sure to give it a few quick tugs, making sure it was as big as she could get; unfortunately, she was trying to avoid premature ejaculation, as she could only get it so hard, and jack it for so long without creaming herself and the living uniform by accident.

A few quick snaps were all Ryuko needed for her member before she relaxed, sweating up a storm as she prepared to send the oddly angled image to Mako and the stranger, adding text that asked, “How's that for a donger?”

After hitting send, Ryuko laughed about after, grinning from ear to ear as she sat back. “Now to see what they think of my cock now!” cackled Ryuko.

To her surprise, the phone pinged her once again within seconds. She had to check it to see if it was indeed the stranger, and of course it was. Except now they revealed themselves right away, with Kiryuin Satsuki standing over Mako, who was likely taking the picture at such a selfie angle. The giant rod was still shoved between her lips, and here she was able to get a proper glimpse of just how badly it caused her to bulge out. And of course, Satsuki was smiling hard, as if to laugh at Matoi's attempt to make her feel small in comparison, laughing immensely over the size comparison.

“What the fuck?” asked Ryuko. “What the FUCK. Is Mako seriously sucking on HER dick?! The only cock her lips need to be around is mine, not hers!”

“Either way, it would make for some nice peace around here...” cackled the living suit.

“Shut up!” Ryuko shouted, standing up from her seat. “We're going to save Mako and show Satsuki who the better fuck is between us!”

“Dueling sisters? Now this is going to make it much more interesting!” Senketsu cackled as Matoi rushed to her sibling's office back at the school.

##

“SATSUKI, YOU WENCH!”

Ryuko had made her way through the student army awaiting her at school with ease, huffing from the running she had to do as a result. Senketsu was in battle mode, fitting tightly against Matoi's physique while showing off the goods. She found her sibling in her white outfit, though she had so much more of her body exposed thanks to her ten inch dong slipping over the crotch while her huge balls were precariously squeezed against it. Mako remained at the president's feet, this time with a collar around her throat with a leash held in the sibling's hand.

“It took you long enough to come out here.” Satsuki said, her face remaining deadpan even as she stood up. “Although I thought you would have tried to hunt her down before you went about your homework activities.”

“Maybe if I knew she was with YOU I'd have been here sooner!” growled Ryuko, who tried and failed to cover up the erection she had been sporting since the video first landed in her hands. “How dare you take my friend and make her suck on your dick?!”

Satsuki lowered her head, a hum escaping her deadpan lips. “I think you're under the wrong impression,” she said, tying Mako's leash to the chair she was sitting at so that she could approach her less successful sister, “Mako actually likes my cock, especially now that she's been able to see what you have in comparison. Isn't that right, my little pet?”

Mako nodded profusely, a great big smile on her lips as she went into motion, even as she was tied to the seat. “Yes yes! Satsuki is right! I love a huge fat cock, especially one that has such length to it! The president may be rude and stubborn but she's hefty, hefty, hefty! While Ryuko is all wimpy, wimpy, wimpy!”

“Hey give me a break here!” Ryuko shouted, her cheeks flushed with embarrassment. “I've saved your ass how many times you ungrateful bitch? And from her associates, nonetheless?!”

“Did Ryuko ever offer her tiny little weiner to me? No!” Mako replied before sticking her tongue out at the would-be rescuer. “But at least Satsuki has a dong big enough to satisfy my needs! I've been hankering for a huge meaty member like that, and only she can satisfy my needs compared to what Ryuko can give me!”

“I can't believe I'm hearing this...” Ryuko grumbled.

“If you doubt it, let me see your member for myself.” Satsuki said, standing almost a foot away from her sibling. Her cock poked up against her tiny bulge, causing Ryuko to shiver from the sensation. As she was able to examine it more closely, without Mako's lips over the crown, she could see that her sister's member was covered in quite a bit of foreskin, with the tip and the urethral slit barely being visible. “Go on! Show me that your dick is bigger than what you pictured, and that I wasn't just viewing it at its actual size!”

With a grumble of regret, Ryuko looked away from her sister as she removed her panties, letting her four inch rod poke out. Satsuki took a moment to study it, seeing that there was a large amount of foreskin even compared to her meat staff, enough that it merely made it look bigger than it actually was. “That's it?!” Satsuki asked, slowly laughing hard at the piece her sibling offered. “Even the length of your foreskin barely makes up for what I have in comparison!”

Ryuko's face had turned bright red at this point, immensely embarrassed as her sister continued to taunt her for her size. Satsuki's slit was starting to drool, with precum oozing out the tip even as she pushed it up against her sister's body. “Look at my cock, Ryuko! Take a look at who among us is the superior sibling!”

“I'd rather not...” grumbled Ryuko, which prompted Satsuki to thrust her hips forward, with enough power in it that it felt like a punch to her gut.

“I said take a look!” Satsuki said, even as Ryuko doubled over to see the length.

“Looking...” Her head was right over the rod, watching it brush up against her groin to compare its size. Even as she pushed right next to it, that wasn't enough to get the immense length of foreskin off the rod, just so she could see how tiny it was under all of that.

“How pathetic,” Satsuki said, swinging her hips so that her rod circled around her sister's, “you don't have the package that I do. I'd say you're barely worthy of having that half of the scissor sword on you. All I can see is a woman compensating for something that you don't have.”

“Shut up...” Ryuko whimpered, even as she kept her brow furrowed. She moaned from the unusual pleasure that came from Satsuki swinging her cock back and forth, slapping against her four inch dick even as she tried to push back the foreskin on her own meaty member.

“You're in MY presence, Matoi!” Satsuki barked, leaning in to cup her sibling's cheeks. “You will do as I say, because I have the biggest weiner in comparison not only to you, but everyone else that attends this school! Even in the TOWN I have a larger cock compared to any adult!”

“Bull.” Ryuko remarked.

“I can set up a rally in the stadiums and prove you wrong if I wanted to! Unless you're willing to accept that you have such a tiny cock!”

Ryuko said nothing to that. She knew if her sister really wanted to, she could do it with a snap of her fingers, and they would already be there thanks to a quick cut, with every man and futa in the town being there with their pants down to prove her point.

“Fine, I have a small penis and I'm horny seeing Mako suck you off,” Ryuko said, “now are we done here?”

“No!” Satsuki barked, pointing her finger at her sister. She grabbed hold of both their rods, squeezing her sibling's tiny dick against her meaty member. She stared at Matoi's face, watching her grow less aggressive with her eyes as the president tugged away at both with one hand. “Pathetic,” Satsuki said, aware fo Ryuko shivering from the repeated tugs against her shaft, “your poor excuse for an extended clit barely fits in my hand. I can tug away at it so easily, but that grotesque extension of your foreskin it what keeps you aroused, isn't it? I'm pulling on that and I see it brings you so much pleasure from my continuous dual masturbation.”

“Yeah...you might be right.” Matoi replied, inhaling with a loud hiss as she tried to keep her saliva in her mouth. She enjoyed the masturbation session Satsuki put her in, pulling so hard that she almost forced Ryuko to stumble into her. Despite the fact they were siblings, she wouldn't exactly put it past her to try something so wrong and lewd between them.

Sure enough, even without that, Satsuki leaned in anyway, locking lips with Ryuko when it was getting obvious that she would stand her ground. Matoi was so horny that she just allowed it to happen, embracing the tongue that her sibling slipped while she continued to let her tug on her thimble while playing the trombone at the same time. Her foreskin pushed back and forth, while her sibling's barely did enough movement to even allow her tip to be revealed, given how much of it there was to work with.

When she was done toying with her sibling, Satsuki pulled back from Ryuko, stepping backwards to watch her sister's expression of dismay that she wasn't made to ejaculate after that. “Mako,” Satsuki said as she took a seat, “get back on my cock! Show your friend what it means to play with a real penis!”

“Yes, Ms. Satsuki!” Mako shouted, giving the president a salute. “I'd love to get on your cock and suck on it until there's nothing left and mmmmmph!” Satsuki proceeded to shove the brunette's mouth down her dick, knowing she wouldn't shut up until pushed to do so. It was a downside to her motor mouth, to be sure, but at least when she was pacified by the pecker it was much easier to handle.

“And you! Stay there and take your punishment!” Satsuki shouted to her sister. “I want you to see for yourself that as good a friend and protector you are, you can't satisfy her like I can!”

Ryuko groaned, already weak thanks to the shock the kiss had on her mind. It may not have done anything all that major to her, but as it was Satsuki her icy gaze and personality still sucked a little bit of energy out of her. The only thing working right now was her four inch pecker, which throbbed as it begged for release.

She watched on as Mako slobbered all over her sister's knob, with loud slurping sounds coming from her mouth. Ryuko swore that she heard her gargling on the saliva as it remained in her orifice, even as she kept Satsuki's member between her lips. Whatever the case, the president hummed in delight, her eyelids shut as she petted away at her hair. “What a good and loyal girl she is,” Satsuki said, further taunting her sibling, “she knows where to go when it comes to a good cock. And there's only one cock good enough for someone like her.”

As she watched Mako let her saliva drool down Satsuki's dick, Ryuko balled her hands into fists, straining herself to fight off the urge to jack it to the scene. She didn't want to give her sister the satisfaction of her tugging on her pecker, knowing she was aroused to the scene of her friend giving the president oral service.

Mako's lips soon popped from the dick, her mouth a slobbering mess thanks to how heavy she left her saliva on Satsuki's knob. She panted heavily, her tongue hanging out of her mouth while strands of saliva and precum bridged between them. The brunette slurped it all up, swallowing it down with a mighty gulp. She then went for her balls, sucking hard on them while the president purred in delight. It was a moment of weakness for even someone of her stature, but she was quick to recover, letting the girl taste her nuts utnil she was ready for more fun.

Looking down at Mako, Satsuki at least had a good view of her while she had her huge balls in her mouth, with her cheeks puffed out by their large size. Her hand wrapped around the shaft, rubbing her saliva into the skin to make it much smoother. Ryuko wondered why, until she realized that it was inevitable that her friend would want to ride her 'evil' sibling's huge erection.

“That will do for now,” Satsuki said, “now let me have that pussy. I want to show your friend how good you are at being my cock cozy.”

“Yes ma'am!” Mako said, standing at attention in an instant with her lips in a smile. She sat on Satsuki's lap, with her cock getting caught between the brunette's ass cheeks, hearing her pant and moan as she continued to work her shaft, just for the sake of rubbing it in more thoroughly. “Satsuki's cock is going to feel nice and smooth inside Mako's pussy, I just know it! It's going to fit as snug as a glove in the wintertime, one that's been sitting on a heater for so long...”

“Mhm...I have my doubts.” Satsuki said, grabbing hold of her shaft. Mako sat up to continue massaging the meat, only for the next drop down on her lap to bring the crown against her folds. The brunette shivered as she unexpectedly let the member push through her folds, letting it stretch out her canal. The foreskin was pushed back so that it could properly fit inside, peeling away from the crown to show off the glans. Ryuko heard the cry of blissful ecstasy, but couldn't do anything; even though it appeared too much for her to handle, it wasn't unwelcomed. Her friend wanted the president's cock in her, no matter how big it was.

“Ah yes! Yes, president Satsuki! Fill me with your cock! I wanna have that ten inch pipe plow me hard and plow me good!” Mako begged. “Oh! Oh! See if you can make it push against my belly, I always wanted to see if that was possible!”

Satsuki watched her sister struggle with the view, her legs squeezed tightly together to keep her small penis between the thighs so as to avoid touching herself. In a way she felt sorry for her, not getting to cum inside her friend. As she held onto Mako's ass, guiding the rhythm of her motions atop the ass, the president let out a sigh, “Fine, Ryuko, you can touch yourself. Come close to Mako and we'll see how much you can get on her.”

There was some relief from Ryuko, but at the same time she didn't know how far her jizz would travel, especially with so much foreskin covering up her tip. She had to peel back quite a lot just to ensure she could even let a drop out on Mako, but it was worth it to feel a bit of chubbiness surrounding her four inch pecker once it was all gone.

Now that her crown felt the air, Ryuko held her cock up to Mako's face, although her friend and host ignored the small cock that was in front of her. The look on her face told her that she enjoyed Satsuki's rod the best, seeing as it was actually doing something by creating friction against her canal. The hard slaps her ass made when dropped down to her sister's lap were clear to Ryuko, not helped by all the begging the brunette made while her tongue stuck out of her smiling mouth.

“Yes, Satsuki, fuck my pussy harder! Drill that cock deep inside of me! Fill it with your baby batter soon, please! I'm so excited to have your cock in me! Please, please! Give me babies, Satsuki, I want my parents to have a next of kin to do better than I can at academics!”

“As if that family has an ounce of the talent I do...” Satsuki grunted, fixated on driving Mako down on her huge shaft. “Although even a fraction of my genes in your family would be an improvement.”

Ryuko continued to stroke herself to the sight of Mako being plowed by Satsuki's stick, hearing her pitch rise with every gasp of air she took. Her eyes rolled back into her head the harder the president plowed into her, with her mouth still going a hundred words a minute even as she was clearly gone mentally.

“Yes! Satsuki! Pump your cock into my cervix! I want to be bred by you! Breed me! Show Ryuko what it means to breed a woman! Show her the true power of womanhood!”

It was then Ryuko felt her four inches stiffen up, grunting as she tried to keep herself from doubling over. She shivered as she curled her chin against her chest, awaiting the inevitable climax that was about to spring from her slit. Unfortunately, it felt like there was more stored inside her nuts than what actually came out. Despite Mako being right in front of her with her mouth hanging open, only about three or four small spurts of cum shot out, just barely reaching the tip on her tongue. There was disappointment coming from Matoi, but it was only going to get worse.

Satsuki held Mako close to her, keeping her ass on her lap just seconds before climax. The two climaxed at the same time, with the president squeezing her jizz inside the tunnel after it splashed off the cervix. The brunette shivered as she squealed like a pig, her legs and toes curling in as she experienced the largest high in her life. The floor became wet with her liquids, with the creamier substance soon escaping out of the snatch. Ryuko watched on in dismay, wishing she was able to ejaculate like that.

With everything a mess and the girls all sweaty, even Ryuko seeming the most exhausted, they spent a few moments recovering from the action. Mako moaned as she kissed away at Satsuki's cheek, thanking her for so much cum. The president purred, looking at her sister. “So are we in understanding of the order of command here?”

“Yeah, sure...” huffed Ryuko.

“Don't forget it, then,” Satsuki said, giving Mako's ass a smack, “you might be better than me in some aspects, but I'm definitely the best all around. Now, try saving up for a few weeks and I might let you cum on Mako again.”

“But...that WAS from saving up after several weeks...” Ryuko said with a look of shock.


End file.
